Require signing on release. Remove forced exit.
Require signing on release. Remove forced exit.

mitchellh/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,mitchellh/vagrant-installers,chrisroberts/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,mitchellh/vagrant-installers,chrisroberts/vagrant-installers,chrisroberts/vagrant-installers